In the arts of moisture cross-linkable polymers containing alkoxysilyl functional group(s), vinylalkoxysilanes or (meth)acryl-substituted alkoxysilanes have been employed as the introduced cross-linking groups.
However, not only the cross-linking speeds of these cross-linking groups are low, but also the moisture permeabilities of the alkoxysilane-introduced polymers which are cross-linked by those cross-linking groups are poor, and therefore it is difficult for moisture to reach the depth of the polymer assembly which results in insufficient cross-linkage at the depth. In addition, since the structure of the cross-linked part is rigid, pliability of the polymer is lost and the cross-linked polymer is apt to have cracks.
As a result of trying to make a basic skeleton of a dimethyl-polysiloxane chain with a great moisture permeability for the purpose of obviating the above-described defects, it has now been found that the depth cross-linkability is greatly improved because the moisture permeability of the resulting polymer is enhanced due to that chain structure.